Air compressor whip sizing?

[6togo]

I'm getting ready to connect my 7.5hp single phase compressor with Mag starter up but not sure on the whip wire sizing. My compressor has a start up of 64amp running amp of 35 and recommended breaker size of 50amp. I ran #6 Romex to the disconnect will a whip with #8 THHN work or will I need to make a whip with #6 wire?

 

[nadogail]

IMHO, either should work. I would use 6 AWG if it is available.

 

[sparky 1971]

I'm getting ready to connect my 7.5hp single phase compressor with Mag starter up but not sure on the whip wire sizing. My compressor has a start up of 64amp running amp of 35 and recommended breaker size of 50amp. I ran #6 Romex to the disconnect will a whip with #8 THHN work or will I need to make a whip with #6 wire?

#8 THHN is fine. I use #8 with 80 amp breakers for 7-1/2 HP compressors.

 

[wyliesdiesels]

I'm getting ready to connect my 7.5hp single phase compressor with Mag starter up but not sure on the whip wire sizing. My compressor has a start up of 64amp running amp of 35 and recommended breaker size of 50amp. I ran #6 Romex to the disconnect will a whip with #8 THHN work or will I need to make a whip with #6 wire?

how did you determine the startup draw? 64a is awfully low. in rush current is typically 4x-8x FLA so it would be hundreds of amps...

Regardless, wire size isnt based on the startup current or the running current. It is based on the corresponding amps in the table FLC

wire size needs to be 125% of NEC table FLC which is 40a for 7.5hp so 50a rated wire. #8 THWN in conduit or #6/2 NM-b

 

[alfredeneuman]

#8 THWN copper for the phase wires and a #10 ground